Oliver d



UNITED STATES PATENT OFF CE.

OLIVER D. WARFIELD, OF SPRINGFIELD, MASSACHUSETTS, ASSIGNOR TO HIMSELFAND FRANK J. WARNER.

CALIPERS.

SPECIFICATION forming part of Letters Patent No. 267,290, dated November7, 1882, Application filed July 21, 1882. (No model.)

To all whom it may concern:

Be it known that I, OLIVER D. WARFIELD, of Springfield, in the county ofHampden and State of Massachusetts, have invented a new and usefulImprovement in Calipers, of which the following is a description andspecification.

The object of my invention is to providea screw-calipers which combinesease of operation with accuracy, and which may be readily adjusted withthe thumb and fingers of the same hand in which it is held when beingused in making measurements; and'I accompl sh this by the mechanismsubstantially as hereinafter described, and illustrated in theaccompanying drawings, in which Figure I is a side view of a calipersmade according to my invention. Fig. II is a vertical section throughthe head, adjusting-screw, and yoke at line A of Fig. I, with the legsof the calipers in side view; and Fig. III is a modification of the yokeand adjusting thumb-nut secured therein.

In the drawings, lrepresents the legs of the calipers, whose extremeupper ends are made flat and of circular form and halved together, andwhich are notched or cut away, as shown at 15, forming an inclined edge,as 3, at the extreme upper end of each leg and above the pivot, as shownclearly in Fig. I. These legs, halved together at their upper ends,are'placed in a vertical slot,as 16, made in the head, as 7, and arepivoted to the head at 2, and a vertical threaded hole is made in thetop of the head 7, into which is dropped first a smalldisk, as 4, andthen a cap, as 5, witha spring, as 6, inside, is turned into thethreaded hole, with the lower end of the spring bearing upon the diskand the latter resting upon the upper ends of the two inclined edges 3,so that the said disk and spring operate to force the two legs apart attheir lower ends by pressing upon said inclined edges. A screw, as S,isfirmly fixed or secured by a pin, as 12, or in any other convenientmanner, in the lower part of the head 7, and extends down between thelegs of the calipers, with a thumb-nut, as 9, extending through a holein a yoke, as 10, turned upon said screw.

This thumb-nut may consist of two disks, as

13 and 14, one provided with a sleeve threaded on the outside at theend, to be turned into a 0 hole in the other disk, and threaded throughthe inside, so that the nut thus formed may be turned upon the screw 8;and the yoke, as 10, may consist of a curved fiat bar with an oblonghole, as 11, near each end, through which the leg 1 extends, as shownclearly in Fig. II.

Instead of making the thumb-nut with two disks, as shown in Fig. II, anda connectingsleeve extending through the yoke, the latter may beprovided with an elongated horizontal hole, as 17, and a single diskplaced therein, with its knurled periphery extending out be yond the baron each side.

, The operation of the invention is as follows: When the parts are inplace, as shown in Fig. 6 II, as the nut, as 9, is turned onto the screw8 the yoke, as 10, is moved upward toward the pivot, and the legs 1 areallowed to be forced apart by the pressure of the disk, as 4, upon theinclined edges 3 at the top, and when the nut 9 is turned down on thescrew 8 the yoke 10 is also moved down and away from the pivot, and theouter ends of the elongated holes 16 in the yoke operate to draw thelegs of the calipers together.

Having thus described my invention, what I claim as new is- An improvedcalipers consisting of two legs pivoted together and to a slotted head,andeach leg provided with an incline at the top, adisk havinga bearingupon said inclines and actuated by a spring to press thereon, a yokeembracing each leg of the calipers, a thumbnut secured in said yoke, andan adjustingscrew secured to said head and extending through a threadedhole in said nut, whereby the legs may be adjusted to any desireddistance apart by turning the nut upon said adjusting-screw,substantially as described.

OLIVER D. WARFIELD.

Witnesses:

T. A. CURTIS,

({HAS. H. Woon.

